Meaning of exception in C# app: “Not a legal OleAut date”?

Question

Does anyone know what this means. Getting this in C# winforms applications:

Not a legal OleAut date

Answer 1

It means that somewhere in the program is attempting to convert to or from an OLE Automation Date outside the valid range 1-January-4713 BC to 31-December-9999 AD. It might have slipped through because OLE Automation Dates are represented as a double.

Start by looking for any uses of the methods:

DateTime.FromOADate

DateTime.ToOADate